


Day Five

by FellQueen (Nikasha)



Series: Kinktober 2019 [5]
Category: Undertale (Video Game)
Genre: Egg Laying, Eggpreg, F/M, Female Reader, Oviposition, Pregnancy Kink
Language: English
Status: Completed
Published: 2019-10-07
Updated: 2019-10-07
Packaged: 2020-11-26 16:00:13
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,765
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20932883
Author URL: https://archiveofourown.org/users/Nikasha/pseuds/FellQueen
Summary: Day FivePrompt: ovipositionPairing: Sans/Female Reader





	Day Five

**Author's Note:**

> Sorry this is late, had a busy day yesterday.

“Are you sure about this?”  
The skeleton you called mate was bridged over you, a concerned look on his face. You could feel his hardness against your thigh, but you knew one word from you and it would be gone like it had never been. You smiled, reaching up to brush your thumb over his cheekbone. He leaned into your touch, nuzzling your hand.  
“I’m sure,” you said softly. “It’s okay.” You reached up and grabbed the spine bared to you by his shirt hanging down and he made a rough noise, eyelights flashing. “Now, come on, bone daddy, fuck me like you mean it.”  
He laughed and leaned down to kiss you. “Please don’t call me that when I’m supposed to be sexy, I can’t handle it.”  
His hand slid up your shirt, tracing over your stomach until he reached the bottom of your bra. He pulled away silently and you were all too happy to reach back to unclip it. Before you could completely tug it off, he was on you again, mouth pressing to yours as he pulled up the hem of your shirt.  
“Sans,” you laughed and it broke into a moan as he nipped at the side of your neck. “Babe, move.”  
He made an unhappy sound, but listened, shifting lower to place nibbles and kisses to your hip and lower belly instead as you tossed away your top and bra.  
Clothes were such a hassle you decided. You finally got Sans to stop for a moment so you could both disrobe, and he was back on you in seconds, making you giggle as he tickled you. “Insatiable much?”  
“There’s a pun in there somewhere, but I’m a little busy,” he commented distractedly, placing sporadic kisses across your cheeks and nose.  
“Yeah ye-ah.” Your voice hitched in the middle of being sassy as Sans pressed a finger against you, then in. You wriggled a bit, discomfited at first, but then relaxed as Sans gave you another kiss.  
His thumb moved to play across your clit and you gave a soft, pleased sigh. “I wouldn’t mind more of that,” he told you with a grin. The edges of it were softened by the gentle look in his eyes. He always got weirdly soft with you. In public, he was all jokes and bravado. In bed, he showed a vulnerability you never wanted anyone else to see.  
Except maybe Papyrus. Not the in bed part, but the vulnerable part. His poor brother had taken enough shit to last a life time.  
That thought was blown out of your mind when Sans curved his finger. You jerked, and he hummed in response, nibbling the soft spot by your jaw. He wiggled his finger around and pressed another one in.  
“I wish I could say put your dick in me already,” you commented weakly. “But I’m guessing it’s...a little different this time.”  
He chuckled. “Yeah. Be patient, love. I don’t want to hurt you.”  
You scoffed a little. He couldn’t hurt you unless he was actively trying, and the likelihood of that was ludicrously low. But still.  
You realized he was grinding into your leg a little, a focused look on his face. Finally he shook his head. “That’ll have to do.”  
You suddenly grabbed his humerus and he stopped, eyes wide with concern. “This...isn’t gonna hurt me or anything, right?” You had talked this over with him before, but suddenly with it such a close reality, you needed reassurance.  
“Heh.” Sans leaned back a little, shaking his head. “Maybe this isn’t such a good idea.”  
“No!” you yelped, pulling him back down. “I do want it, I do. I’m not afraid of you. Just...afraid of my human-ness. I guess.” Words were hard.  
Sans still looked hesitant, but he answered. “It won’t hurt you,” he said confidently. “Other monsters have tried it by now and it was fine.” He scrubbed the back of his neck with a hand. “If anything, humans are a safer place to put eggs than even other monsters. You have, like, real physical anatomy and organs where us monsters are magic. And you’re harder to, um, to hurt.”  
You noticed the pinch between his brows and reached up to smooth it out. “I trust you,” you said, and that was enough.  
Sans still looked a little wary, but he nodded. He kissed your forehead, then your mouth. It became heated and you were sufficiently distracted until you felt something warm pressed against your pussy.  
You sucked in a breath and Sans hummed soothingly, nipping at your tongue. The tube slid inside you easily enough, the smooth texture odd in your passage. You squirmed a little. It was made of Sans’s magic, a familiar tingling and pulse by now, but usually it didn’t feel so smooth and straight. Sans grimaced a little and it shifted, widening as he focused.  
You closed your eyes. “Not so bad,” you murmured.  
He chuckled, only a little strained. “It’ll get better.” His thumb was still gently moving and you focused on that, breathing evenly.  
Sans licked your neck and down to your collarbone where he set his teeth lightly. He started nibbling a bruise into your skin, and you squirmed, hands going to the back of his ribcage. Your breath hitched as the magic inside you pressed against a spot that put sparks in your belly.  
Sans moaned, feeling your wetness leaking around him. “Fuck.” His hips jerked instinctively, but when you glanced down, the magic wasn’t actually connected there, but somewhere inside his ribcage that you couldn’t quite discern. He was just grinding his pelvis into the bed, but the bone was glowing. Clearly he was getting something out of it.  
Sans suddenly bit down a little harder and you gasped, arching against his body. Your fingers dragged over his back and he moaned.  
You felt the magic inside of you pulse. It swelled where it entered you, pushing the boundaries already set by its girth. But it didn’t ache, just felt like pressure as it slowly pushed through into you.  
You couldn’t find words. It felt odd, but also nice. A constant pressure was in your vagina as it moved up, massaging the walls and making you twitch. You exhaled sharply and your hips jerked as it pushed into your womb.  
You opened your eyes. You didn’t remember closing them. Sans was watching you with rapt attention, hungry and worried all in one.  
“Okay?” he said, eyelights scanning your expression.  
“Yeah,” you breathed. You felt the tube in you begin to contract again and whimpered. You couldn’t tell if you were excited or nervous.  
Sans seemed reassured, though. “You’re doing amazing.” The magic started pushing inside of you like Sans was fucking you, and you definitely moaned then, legs lifting to hook around his waist. He leaned down and kissed your neck.  
A second egg pressed its way down your passage and you felt it like Sans pressing his dick into you at the beginning of a night. Once it was settled, you whined, definitely in greed this time. “More.”  
Sans grinned. “There’s my good girl.”  
The eggs came faster, moving smoother and quicker. When they left Sans’s magic to meet your warmth, it was the strangest sensation, but pleasant. Not something you could really describe. You lost count somewhere along the line.  
“Last one,” Sans breathed and you shuddered against him, hugging him. “Soon, beautiful.”  
It almost seemed painfully slow, the last egg. Sans’s magic lead it along, but it paused at one point. It felt like the damn thing was in your throat instead of your pussy.  
Finally, it shuddered forward. As it pressed past that sensitive point, you felt a surge of unexpected pleasure. You cried out, your slick drenching the egg and Sans’s magic, unable to escape with as full as you were. You started trembling, the egg still pressing against that spot on its slow way further. “Sans,” you gasped, arching your back like it might help.  
“Shhh.” He nuzzled your cheek. “It’s okay, it’s okay.”  
It passed. You fell limp, covered in sweat and panting. Sans was groaning, hips pushing into the bed as he stared at you. “Good girl,” he said again, hand moving to rest on your hip.  
The final egg settled. Sans sighed, almost in relief, but you just pulled him down and bit his shoulder, earning a loud yelp. The magic in you dissipated and you grunted at the bizarre empty feeling. You started to unwrap your legs, but he stopped you with a hand on your thigh. “Hang on, babe.”  
You blinked your eyes open blearily, and your conversation came back to mind. “Oh, right.” You weren’t quite done.  
Sans just smiled and kissed you. A quick flash of his eyes, and he was pressing his cock into your cunt, easily moving forward until he was seated. It didn’t feel as big as usual, but you supposed that made sense with how stretched you were. He was still so warm and his magic faintly hummed in a pleasant way.  
Sans moved his hips slowly, working you back up. He was breathing hard, trying to hold himself back. With his distraction, words he didn’t usually say kept slipping out. “You’re so soft.” “You’re mine.” “I love touching you.”  
His eyes slide open a little. “One day I’ll put my kids in you.”  
Your eyes widened. Before you could say anything, he fucked into you hard, and it ripped your breath away.  
When Sans came, it seeped around the eggs and back down and out of you. You almost sobbed, so full of him and the eggs.  
Sans leaned back and ran his hand over your slightly distended belly. “You look beautiful like this,” he murmured.  
You were still catching your breath, but you reached up to poke his nasal bone. “That’s a conversation for another time,” you told him softly.  
He lit up like a beacon, shyly looking away. “Ah, yeah. Sorry.”  
You rubbed your own hand across the small bump. It felt good. You felt needed. “Shyren will be happy.”  
Sans hummed, nuzzling your jaw. “Thank you, love. This means a lot to us monsters.”  
“I know.” You nuzzled back. “If I can help out a dying species by something that feels good, I won’t complain.”  
Sans shook his head. “You’re too good for me.”  
You hummed. “Maybe.” You used your legs still around his hips to pull him into you again and he gasped. “Maybe not. I’m still needy here.”  
He growled, pleased. “I’d be happy to help.”

**Author's Note:**

> List used:  
https://twitter.com/idek_uggy/status/1178349575725174786?s=21
> 
> Next is face-fucking


End file.
